Originally Posted by AK74play
The plate is only used for wooden stocks. The Hogue don't require one.
Correct. The part is called the stock bearing plate and it is only used on wood stocks. The purpose is to hold the stock slightly off the receiver which keeps it from spliting or chipping from the recoil. All those woods stocks you see with small chips of wood broke off right where the receiver meets the stock is because someone did not use the stock bearing plate.
Synthetic stocks or metal stock adapters do not require a stock bearing plate. Also, if you fail to remove the stock bearing plate when changing to a synthetic stock you will notice a gap between the stock and receiver.